1 files changed, 1 insertions, 0 deletions
diff --git a/cpp/001test b/cpp/001test
index 0db10e4b..2319348b 100644
--- a/cpp/001test
+++ b/cpp/001test
@@ -49,6 +49,7 @@ if (argc == 2 && is_equal(argv[1], "test")) {
 }
 // pass in a set of line numbers in test_file to run just those tests
 if (argc > 2 && is_equal(argv[1], "test") && is_number(argv[2])) {
+  assert(Next_recipe_number < 1000);  // see vm layer
   for (int i = 2; i < argc; ++i) {
     run_test(to_int(argv[i])-1);
   }